Bhai Mani Singh Ji took amrit at Anandpur in 1699 and served Guru Gobind Singh Ji as a scribe. He wrote out the Damdami recension of the Guru Granth Sahib Ji to the Guru's dictation at Talwandi Sabo.
After 1708 he was sent to Amritsar as granthi of the Harmandir, at a time when the Khalsa was proscribed and the shrine was under Mughal control for long periods.
In 1737 he applied to the governor of Lahore, Zakariya Khan, for permission to hold the Diwali gathering at Amritsar, agreeing to pay a tax of five thousand rupees. Troops were posted around the town, the sangat did not come, and the money could not be raised. He was arrested and ordered to be cut apart at the joints. The account says the executioner began at the wrist and he pointed out that the order specified joints, and that the fingers had joints too.
He is credited with arranging the Guru Granth Sahib Ji by raga in the form now standard, and with the compilation known as the Bhagat Ratnavali.
Gurdwara Shaheed Ganj at Lahore marks the place of execution.
A large number of his sons and grandsons are named in the martyrologies of the same decades. The family is the clearest case in the record of a single household absorbing the whole of that period's cost.
He was executed at Lahore around 1737 for failing to pay a tax agreed for a gathering at Amritsar that the administration then prevented.
The account of his execution, dismembered joint by joint, is among the central martyrdom narratives, and he is remembered as a scholar as much as a martyr.